Over the years, various techniques and devices have been developed to help a person accurately aim a weapon such as a rifle. One common approach is to mount a sight or scope on the weapon. A person then uses the sight or scope to view an intended target in association with a reticle, often with a degree of magnification. Although existing weapon sights have been generally adequate for their intended purposes, they have not been satisfactory in all respects.
For example, it is very common for a solder to carry both a rifle and a grenade launcher. The grenade launcher is detachably coupled to the rifle, thereby effectively giving the soldier an integrated weapon that can selectively deliver either of two different types of munition. Typically, however, one sight is provided for the rifle, and a physically separate sight is provided for the grenade launcher. Further, these sights are configured so that, at any given point in time, each sight can be used with only a single type of munition. Moreover, the sight for the grenade launcher is often mounted near the outer end of the rifle barrel, thereby adding weight at a location spaced from the center-of-mass of the overall weapon, and thus necessitating greater effort by a soldier to swing the weapon to bear and then hold it on a target.
A further consideration is that, where a soldier has a grenade launcher mounted on a rifle, the soldier may be able to selectively use different bullets of the proper caliber in the rifle, or selectively use different types of grenades with the grenade launcher. Moreover, it may be a simple matter for the soldier to detach one type of grenade launcher from the rifle and quickly attach a different type of grenade launcher. Existing weapon sights provide little or no capability for quick and accurate adjustment in the field to accommodate changes in munition type and/or weapon type.
To the extent some existing weapon sights include electronic circuitry that can provide a user with electronically calculated information to assist in aiming the weapon, this information is often not visible within the same field of view in which the target is visible, and is often presented digitally in the form of alphanumeric characters that are sometimes difficult to understand and use. A further consideration relates to the extent to which calculations based on a particular target ranging event remains available for use by a user.
Still another consideration is that some weapon sights include a laser rangefinder. However, in order to achieve a high transmission efficiency for both the outgoing pulse and the reflected energy, these laser rangefinders typically have a first aperture for the outgoing pulse, and a separate second aperture for the reflected energy. Other existing laser rangefinders use a single aperture, but in association with a beam splitter having a transmissivity of approximately 50% for the laser wavelengths involved, resulting in approximately a 50% loss for the energy of the transmitted pulse, and another 50% loss for the reflected energy. This is undesirable, because it reduces the maximum range that can be measured by the rangefinder. Moreover, this is highly inefficient, which makes it undesirable for a battery-operated weapon sight, where any waste of energy reduces the amount of time that the weapon sight can operate before the battery becomes discharged.